Continuous-wave fiber lasers can generate multiple kilowatt laser beams with relatively superior beam quality. Power scaling of fiber lasers is limited by nonlinear processes in the fiber and by thermal effects. Methods are needed to address these limitations in order to enable further power scaling of fiber lasers in a practical manner. Additionally, various applications of laser diode sources, such as direct diode material processing, illumination, and pumping of solid state lasers, could benefit from brighter optical outputs.